One common theme is the exploration of innocence. When Merlin is de - aged, he often regains a sense of childlike wonder and innocence. This is contrasted with his usual more jaded self as an adult in the show. For example, his reactions to magic might be more pure and unrestrained.
There's also a series where Merlin is de - aged due to a spell gone wrong. In this fanfiction, we see a more innocent and yet still powerful Merlin. It delves into how the characters around him, like Gaius, have to take on different roles to protect and guide this younger Merlin. It's quite interesting as it shows a different side of the well - known characters. The story also focuses on how Merlin's de - aged state affects the political situation in Camelot, as his presence and powers are always a significant factor in the kingdom's affairs.
One popular 'de aged merlin fanfiction' is 'The Young Merlin's Adventures'. It shows Merlin as a child in Camelot and how his magic still manages to get him into all sorts of interesting situations. Another is 'Merlin: De - Aged and Discovering'. This one focuses on how the de - aged Merlin rediscovers his relationship with Arthur in a new light.
Fanfiction.net is also a good place to look. Just type 'de aged merlin' in the search box and it will show you relevant fanfictions. However, the quality may vary, so you might need to read a few to find the really good ones. Some writers also post their 'de aged merlin fanfiction' on their personal blogs or Tumblr pages, but it can be a bit harder to find them that way.
One great female Merlin fanfic could be one where she uses her magic in unique ways to save Camelot. For example, in a story she might use her powers to heal the knights secretly when they are injured in battle. This would add an interesting twist as she has to hide her actions from Uther.
If Merlin died in the fanfiction, it could trigger a series of tragic events. The balance of power could tip, and the villains might seize the opportunity to attack. It could also bring out hidden strengths in the remaining characters as they try to cope with the loss.
In a more humorous take on the 'Merlin tied to a bed' fanfiction, it could be that Merlin has fallen ill and the overly - protective Gaius has tied him to the bed to make sure he rests. Merlin, being the active person he is, complains constantly. Arthur comes to visit and teases Merlin about finally being still for once. Meanwhile, Merlin tries to convince Arthur to let him loose, promising that he'll be fine. Eventually, Gaius relents and unties Merlin, who then immediately starts bustling around the room.
One possible reason could be a magical curse. In many Merlin fanfictions, magic is often used as a plot device. A dark sorcerer might cast a spell on Merlin to make him forget certain things, perhaps to prevent him from using his powerful magic to oppose them. Another reason could be a self - imposed forgetting due to trauma. Merlin has witnessed and endured a great deal of pain and suffering. To protect his own mental state, his mind might subconsciously block out certain memories.